Basf Aktiengesellschaft

Styrolution Europe Gmbh

Marian Mours

Christian Schade

Peter Ittemann

Marco Krüger

Bernhard Czauderna

Karl-Heinz Wassmer

Norbert Güntherberg

Ruediger Krech

Rainer Anderlik

Guenter Scholz

Sven Lawrenz

Jens-Uwe Schierholz

Christoph Bahr

Jürgen Hofmann

Paulus Schmaus

Hartmut Heinen

Horst Papenfuss

Michael Sauer

Rainer Bardon

Michael Kirschey

Gitta Egbers

Martin Roos

The present invention relates to a process for the continuous production of thermoplastically processable polyurethane elastomers, by metering a polyisocyanate (A), a proportion of 1-80 equivalent%, based on the isocyanate group content of the polyisocyanate (A), of a compound (B) having an average of at 1.8-3.0 hydrogen atoms having Zerewitinoff activity, with an average molar mass of 450-5000 g/mol, and a proportion of 12-99 equivalent%, based on the isocyanate group content of the polyisocyanate (A), of a chain extender (C), into a self-cleaning twin-screw extruder whose diameter is 32-62 mm, which is operated at shear rates above 6000 sand residence times of 1-20 seconds, and then bringing the mixture from the self-cleaning twin-screw extruder into a second apparatus in order to complete the reaction.

Method for the continuous production of thermoplastically-processable polyurethane elastomers

Continuous process for preparing polyoxymethylene homo- or copolymers by bulk polymerization of the monomers in the presence of cationic initiators, and also, if desired, in the presence of regulators, where during the polymerization both the monomers and the polymer are present in molten form and, if desired, the polymer is then deactivated, and the melt is discharged, cooled and pelletized, which comprises discharging, cooling and pelletizing the polymer at an elevated pressure and in the presence of a liquid.

Preparation of polyoxymethylenes

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Weisenheim, Germany

Marian Mours